www.felinecrf.org
www.felinecrf.com

These are excellent websites with a lot of advice. Please do not despair. With Filou it was diagnosed when he was 9 years old and he lived in excellent life quality until he was 15. In the beginning it was diet only - and when checking the levels they progressed very slowly and even became better.
In the last years it was weekly sub-q fluids for him.
I would always go that same road- he was a happy boy.

Good luck for Willy and you.

P.S. BTW Filou who also preferred dry food really loved the Royal Canin renal food in pouches.